Friday’s dusting of snow ushering in frigid air, setting stage for potentially significant storm

The cold sets in, temperatures will be below average throughout the five day for the first time in a long time.

Anywhere from a dusting to as much 2 inches of snow fell across the region Friday, marking a return of wintry weather expected to culminate in a significant storm early next week.

A relatively weak low-pressure system was responsible for half an inch of snowfall in northwest Baltimore, an inch in Eldersburg and 2.2 inches in the Millers area of northeastern Carroll County, near the Pennsylvania line, according to the National Weather Service.

Accumulation of as much as 3 inches in Western Maryland led to school delays in Garrett and Allegany counties, as well as at Frostburg State University.

Only a trace of snow was reported at Baltimore’s point of record, Baltimore-Washington International Thurgood Marshall Airport. That means the season’s snowfall tally remains at 0.7 inches, tied with the winter of 1949-1950 as Baltimore’s least snowy on record.

Accumulations were limited for much of the region because air temperatures were hovering a few degrees above freezing and pavement was warm. On Thursday, temperatures had climbed to 71 degrees at BWI.

But a storm that meteorologists expect will bring heavy snow from Virginia to Maine early next week is likely to end the region’s snow drought.

Unseasonably cold air moved in behind Friday’s snow showers, helping set the stage for a potentially significant dumping of snow and ice.

BWI topped out at 54 degrees Friday, and over the weekend highs are only expected in the 30s, with lows in the teens and 20s.

Baltimore Health Commissioner Dr. Leana Wen issued a "code blue" advisory for Friday night through Saturday morning, urging homeless people to visit shelters and residents to check on vulnerable neighbors.

That means the ground will be plenty cold if a large, intense system commonly known as a Nor'easter forms Monday, as meteorologists expect. The storm is expected to remain over Maryland from late Monday through Tuesday.

Forecasters at the weather service's Baltimore/Washington office said the storm's local impact will depend on its track and timing — the region could find itself close to the line dividing heavy snow and mixed precipitation, or just cold rain.

A few factors could favor a significant impact — the timing of the storm, likely overnight when the intensifying March sun is down and the abundance of cold air ahead of it, they said.

But it’s also possible that the storm’s development and track could leave Maryland on its warm side, while it dumps snow across the Northeast.

"Given the highly anomalous cold in place before the storm and potential phasing, this system bears close watching in the coming days," the forecasters wrote.